<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style type="text/css">
        .box {
            width: 200px;
            height: 200px;
            margin: 100px;
            background: green;
            /* 统一设置 */
            border: 10px solid red;

            /* 单独设置每一个 */
            border-width: 20px;
            border-style: dashed;
            border-color: aqua;

            /* 单独设置每一个方向 */
            border-top: 10px solid red;
            border-bottom: 10px dashed peru;
            border-left: 10px dotted gold;
            border-right: 10px double blue;
            
            /* 分别对上下左右设置不同的属性 */
            border-top-width: 10px;
            border-top-style: dashed;
            border-top-color: gray;
        }
    </style>
</head>
<body>
    <div class="box"></div>
</body>
</html>